Gosh! I'm very late to this party, but have just been sent here by Benjamin Todd via an 80k hours LinkedIn post! I am a psychologist - with feet in both applied (therapeutic) practice and research. Being the age I am, and already in a second career, I have been looking for ways to have more impact given my existing skills/knowledge/experience - which would be in psychological well-being (however that is determined within a given cultural context), and I could niche down more into behaviour change, substance misuse, and addictions. Broadly, I practice elements of cognitive-behavioural therapies.
I certainly think how one measures/tracks well-being/'happiness'/life satisfaction/'the absence of symptoms/the presence of good-health/ etc. is key here. For instance, rather than a scale measuring presence/absence of, say, "depression" (however that is defined within a culture) - I would know more about how the presence/absence of this 'depression' is affecting someone if I knew, for example, how many hours they spent in bed, hours they spent crying, how many times they bathed or did the dishes in the past week, completed tasks they had set themselves etc. Apps I think need to have some way of tracking the behaviours and signifiers for the individual that show they are 'more' or 'less' symptomatic of the 'problem'. This would mean that the user input and tracked more meaningful data - along a more quantified self type of strategy - which would hopefully keep them more engaged with the intervention.
Anyhoo - I shall follow this thread and other discussions around mental health and well-being closely!
kind regards EA community!